Rib fracture displacement worsens over time

Purpose Rib fractures (RF) occur in 10% of trauma patients; associated with significant morbidity and mortality. Despite advancing technology of surgical stabilization of rib fractures (SSRF), treatment and indications remain controversial. Lack of displacement is often cited as a reason for non-operative management. The purpose was to examine RF patterns hypothesizing RF become more displaced over time. Methods Retrospective review of all RF patients from 2016-2017 at our institution. Patients with initial chest CT (CT1) followed by repeat CT (CT2) within 84 days were included. Basic demographics were obtained. Primary outcomes included RF displacement in millimeters (mm) between CT1 and CT2 in three planes (AP = anterior/posterior, O = overlap/gap, and SI = superior/inferior). Displacement was calculated by subtracting CT1 fracture displacement from CT2 displacement for each rib. Given anatomic and clinical characteristics, ribs were grouped (1-2, 3-6, 7-10, 11-12), averaged, and analyzed for displacement. Secondary outcome included number of missed RF on CT1. Non-parametric sign test and paired t test were used for analysis. Significance was set at p < 0.002. Results 78 of 477 patients with RF on CT1 had CT2 during the study period: primarily male (76%) and age 55.8 +/- 20.1 with blunt mechanism of injury (99%). Median Injury Severity Score was 21 (IQR, 13-27) with Chest Abbreviated Injury Score of 3 (IQR, 3-4). Median time between CT1 and CT2 was 6 days (IQR, 3-12). Missed RF rate for CT1 was 10.1% (p = 0.11). Average fracture displacement was significantly increased for all rib groupings except 11-12 in all planes (p < 0.002). Conclusion RF become more displaced over time. Pain regimens and SSRF considerations should be adjusted accordingly.